Clydesdales/Athenas (200+ lb / 91+ kg) - mile/calorie exchange rate

I thought running a mile at 7 minutes and walking at 12 minutes would burn the same calories, or that is what I had read in some magazines.

So I decided to use my Garmin Forerunner 305 to compare it with heart rates. I did 10 miles at a slow 15.3 mph pace and burned approximately 75 calories per mile. Average heart rate of 93 bpm

Then I did a 6 mile ride at 24.8 mph pace, and burned 88 calories per mile. Average heart rate of 127 bpm.

These are all on the rollers, so it is the same thing as far as conditions go. So, they are similar in calories burned, but not the exact same as far as calculating using heart rate. Since I am trying to do more things in my life, triathlon, duathlon, 10k, half marathon, etc..., I thought I would look at calories burned.

Now how do I make the transition of calories burned per hour to know when and how much to refuel when on century rides or olympic distance triathlons. How much can my body actually take in during an event and should it all be through the drinks, or should it be through food?

Just eat every hour. You won't be able to eat as many calories as you burn and digest it. So try for a couple hundred calories an hour with lots of water.

Also, you'll find that calorie numbers on the Garmin are rather, um, optimistic. They overestimate anywhere from 30 to 50%. Don't use those numbers to figure out your diet. You'll gain weight.

I remember long ago reading a book, in which the author promoted the idea that someone with more muscle mass would actually burn more calories in day-to-day activity than somebody of equal weight but less muscle. His idea was that part of this is due to the more muscular person simply being more active, and part due to the assumed fact that bigger muscles use more calories to do the same amount of work. I don't know if all this is true or fantasy, but at least it sounds reasonable. Anyway, one of the conclusions was that assuming that calories burned during exercise were all the benefits you got out of the exercise was pretty misleading. You'll notice those numbers always look disappointingly low. Run a marathon, and you've burned off a banana split or something like that.

That's interesting...I remember reading sometime ago that it takes the same amount of energy to move mass over a distance. So, run, walk, crawl one mile will burn the same amount of energy (calories). The rub is what happens after you are done...if you ran a 5 min. mile, you will still be burning energy after you stop...if it was a 40 min. stroll, your pretty much done when you stop.

Update:

10 miles at 18.1 mph average = 78 calories/mile at average HR of 106

10 miles at 22.9 mph average = 98 calories/mile at average HR of 125


So mile per mile doesn't seem to burn the same calories for me as this is the same ride on the rollers. With 10 miles, stretch, 10 miles, stretch. Have to go play some music so it was a short hour ride on the bike.

Thoughts????